// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab

#include <string.h>

#include <iostream>
#include <map>

#include "include/types.h"

#include "common/Formatter.h"

#include "rgw_acl.h"
#include "rgw_user.h"

#define dout_subsys ceph_subsys_rgw

using namespace std;

void RGWAccessControlList::_add_grant(ACLGrant *grant)
{
  ACLPermission& perm = grant->get_permission();
  ACLGranteeType& type = grant->get_type();
  switch (type.get_type()) {
  case ACL_TYPE_REFERER:
    referer_list.emplace_back(grant->get_referer(), perm.get_permissions());
    break;
  case ACL_TYPE_GROUP:
    acl_group_map[grant->get_group()] |= perm.get_permissions();
    break;
  default:
    {
      rgw_user id;
      if (!grant->get_id(id)) {
        ldout(cct, 0) << "ERROR: grant->get_id() failed" << dendl;
      }
      acl_user_map[id.to_str()] |= perm.get_permissions();
    }
  }
}

void RGWAccessControlList::add_grant(ACLGrant *grant)
{
  rgw_user id;
  grant->get_id(id); // not that this will return false for groups, but that's ok, we won't search groups
  grant_map.insert(pair<string, ACLGrant>(id.to_str(), *grant));
  _add_grant(grant);
}

uint32_t RGWAccessControlList::get_perm(const RGWIdentityApplier& auth_identity,
                                        const uint32_t perm_mask)
{
  ldout(cct, 5) << "Searching permissions for identity=" << auth_identity
                << " mask=" << perm_mask << dendl;

  return perm_mask & auth_identity.get_perms_from_aclspec(acl_user_map);
}

uint32_t RGWAccessControlList::get_group_perm(ACLGroupTypeEnum group,
                                              const uint32_t perm_mask)
{
  ldout(cct, 5) << "Searching permissions for group=" << (int)group
                << " mask=" << perm_mask << dendl;

  const auto iter = acl_group_map.find((uint32_t)group);
  if (iter != acl_group_map.end()) {
    ldout(cct, 5) << "Found permission: " << iter->second << dendl;
    return iter->second & perm_mask;
  }
  ldout(cct, 5) << "Permissions for group not found" << dendl;
  return 0;
}

uint32_t RGWAccessControlList::get_referer_perm(const std::string http_referer,
                                                const uint32_t perm_mask)
{
  ldout(cct, 5) << "Searching permissions for referer=" << http_referer
                << " mask=" << perm_mask << dendl;

  /* FIXME: C++11 doesn't have std::rbegin nor std::rend. We would like to
   * switch when C++14 becomes available. */
  const auto iter = std::find_if(referer_list.crbegin(), referer_list.crend(),
    [&http_referer](const ACLReferer& r) -> bool {
      return r.is_match(http_referer);
    }
  );

  if (referer_list.crend() == iter) {
    ldout(cct, 5) << "Permissions for referer not found" << dendl;
    return 0;
  } else {
    ldout(cct, 5) << "Found referer permission=" << iter->perm << dendl;
    return iter->perm & perm_mask;
  }
}

uint32_t RGWAccessControlPolicy::get_perm(const RGWIdentityApplier& auth_identity,
                                          const uint32_t perm_mask,
                                          const char * const http_referer)
{
  uint32_t perm = acl.get_perm(auth_identity, perm_mask);

  if (auth_identity.is_owner_of(owner.get_id())) {
    perm |= perm_mask & (RGW_PERM_READ_ACP | RGW_PERM_WRITE_ACP);
  }

  if (perm == perm_mask) {
    return perm;
  }

  /* should we continue looking up? */
  if ((perm & perm_mask) != perm_mask) {
    perm |= acl.get_group_perm(ACL_GROUP_ALL_USERS, perm_mask);

    if (false == auth_identity.is_owner_of(rgw_user(RGW_USER_ANON_ID))) {
      /* this is not the anonymous user */
      perm |= acl.get_group_perm(ACL_GROUP_AUTHENTICATED_USERS, perm_mask);
    }
  }

  /* Should we continue looking up even deeper? */
  if (nullptr != http_referer && (perm & perm_mask) != perm_mask) {
    perm |= acl.get_referer_perm(http_referer, perm_mask);
  }

  ldout(cct, 5) << "Getting permissions identity=" << auth_identity
                << " owner=" << owner.get_id()
                << " perm=" << perm << dendl;

  return perm;
}

bool RGWAccessControlPolicy::verify_permission(const RGWIdentityApplier& auth_identity,
                                               const uint32_t user_perm_mask,
                                               const uint32_t perm,
                                               const char * const http_referer)
{
  uint32_t test_perm = perm | RGW_PERM_READ_OBJS | RGW_PERM_WRITE_OBJS;

  uint32_t policy_perm = get_perm(auth_identity, test_perm, http_referer);

  /* the swift WRITE_OBJS perm is equivalent to the WRITE obj, just
     convert those bits. Note that these bits will only be set on
     buckets, so the swift READ permission on bucket will allow listing
     the bucket content */
  if (policy_perm & RGW_PERM_WRITE_OBJS) {
    policy_perm |= (RGW_PERM_WRITE | RGW_PERM_WRITE_ACP);
  }
  if (policy_perm & RGW_PERM_READ_OBJS) {
    policy_perm |= (RGW_PERM_READ | RGW_PERM_READ_ACP);
  }
   
  uint32_t acl_perm = policy_perm & perm & user_perm_mask;

  ldout(cct, 10) << " identity=" << auth_identity
                 << " requested perm (type)=" << perm
                 << ", policy perm=" << policy_perm
                 << ", user_perm_mask=" << user_perm_mask
                 << ", acl perm=" << acl_perm << dendl;

  return (perm == acl_perm);
}


